Leptin, Acting at Central Level, Increases FGF21 Expression in White Adipose Tissue via PPARβ/δ

The altered function of adipose tissue can result in obesity, insulin resistance, and its metabolic complications. Leptin, acting on the central nervous system, modifies the composition and function of adipose tissue. To date, the molecular changes that occur in epididymal white adipose tissue (eWAT) during chronic leptin treatment are not fully understood. Herein we aimed to address whether PPARβ/δ could mediate the metabolic actions induced by leptin in eWAT. To this end, male 3-month-old Wistar rats, infused intracerebroventricularly (icv) with leptin (0.2 μg/day) for 7 days, were daily co-treated intraperitoneally (ip) without or with the specific PPARβ/δ receptor antagonist GSK0660 (1 mg/kg/day). In parallel, we also administered GSK0660 to control rats fed ad libitum without leptin infusion. Leptin, acting at central level, prevented the starvation-induced increase in circulating levels of FGF21, while induced markedly the endogenous expression of FGF21 and browning markers of eWAT. Interestingly, GSK0660 abolished the anorectic effects induced by icv leptin leading to increased visceral fat mass and reduced browning capacity. In addition, the pharmacological inhibition of PPARβ/δ alters the immunomodulatory actions of central leptin on eWAT. In summary, our results demonstrate that PPARβ/δ is involved in the up-regulation of FGF21 expression induced by leptin in visceral adipose tissue

Validation of coffee by-products as novel food ingredients

This research aimed to validate coffee husk, parchment and silverskin as new health-promoting food ingredients. Characterization of the novel ingredients was carried out by Raman and infrared spectroscopy and analysis of total phenolic compounds, chlorogenic acid, caffeine and dietary fiber. Antioxidant properties of the novel ingredients were tested by ABTS and intracellular ROS formation in HepG2 cells. Pesticides, mycotoxins, acrylamide and acute toxicity experiments following OECD Test Guidelines 425 were performed to assess the food safety of extracts, solid residues and raw materials. Husk and silverskin are proposed as a source of two food ingredients: aqueous extracts enriched in phytochemicals and antioxidant dietary fiber while parchment is proposed as a natural source of antioxidant dietary fiber. No lesions were found in selected isolated vital organs from treated animals. Coffee by-products can be converted into safe food ingredients allowing a whole food waste recovery. Analyses of contaminants are essential for achieving this goal.Ministerio de Economía y CompetitividadSUSCOFFEESección Dptal. de Nutrición y Ciencia de los Alimentos (Veterinaria)Fac. de VeterinariaTRUEpu